Many of the parts Highland machines are small and complex. Juxtaposed against the tip of a ballpoint pen, the part on the right is not a chip, but a prototype bonescrew that includes two tiny holes.

These milling sleeves and other components of the Swiss-type lathes are removed and cleaned after every job.

After every job, the shop dips tools into the melting tank on the table shown here. Preserved in plastic, the tools are organized in drawers to be either reused or examined for clues about how to improve that particular job.

To improve chip control, every machine in the shop is equipped with a Brookdale high-pressure coolant pump (left). The Tri-Mist filtration units (right) use electrostatic technology to capture coolant mist particles. Without these units, Mr. Erickson says, the entire shop would be filled with a fog of oil.

At Highland Products, a Mentor, Ohio-based job shop specializing in
CNC Swiss-type machining, unattended production is more than just a
process—it’s a philosophy. While high-tech equipment and machining
expertise contributes to the shop’s success, its mindset about
lights-out manufacturing is just as important. Running lights-out
allows the shop to commit to a 40-hour work week with no overtime
(which is sometimes an obstacle to finding new employees). Beyond the
40 hours that are supervised, unattended machining provides all the
capacity this busy shop needs.

The
first step to running unattended is to believe you can do it, Mr. Nolan
says. It’s a simple, but fundamental, philosophical commitment.

For
Mr. Erickson, who founded Highland more than 30 years ago, obtaining
this belief began with an unexpected move from using conventional
lathes to specializing solely in CNC Swiss-type machining.

Shifting The Focus

“I basically backed into Swiss turning,” Mr. Erickson says. In the
beginning, the shop’s equipment primarily consisted of conventional
turning centers. When a customer suggested a Swiss-type turning center
for an order of 500 medical parts, Mr. Erickson purchased his first
Swiss-type from Marubeni Citizen-Cincom
(Allendale, New Jersey). Unfortunately, the customer canceled the
order, and Highland was left with a sophisticated machine for which it
seemed to have no use.

Luckily, a neighboring job shop was having trouble machining a hydraulic
piston, a tough part it had been making in two operations on a
conventional lathe. After asking the distributor that sold him the
Citizen lathe (Concentric Corporation, Cleveland, Ohio) to help set up
the new machine, Mr. Erickson completed the part in 88 seconds. This
was much better than the neighboring shop’s cycle time of 25 minutes.
Soon after, Highland was awarded a contract to produce 2,500 of the
pistons.

It didn’t take long for Mr. Erickson to realize the benefits that
CNC Swiss-type machines could bring. Competition was high for work that
could be done on conventional turning centers, and using Swiss-type
turning centers to machine small, often complex parts was a niche he
was more than willing to fill. In addition, when equipped with bar
feeders from LNS America
(Cincinnati, Ohio), the shop’s new Swiss-type machines were easy to set
up for lights-out operation. Shortly after Mr. Nolan came onboard,
ostensibly to run the new Swiss-type machines while Mr. Erickson
focused on the conventional turning centers, the two decided to
concentrate solely on Swiss turning.

The Right Tools For The Job

Today, Highland has 15 CNC Swiss-type turning centers, consisting
mainly of Citizen M- and L-series machines. These are used to run jobs
for the medical, aerospace, automotive and telecommunications
industries (among others) in part quantities ranging from one to 1
million. Typical jobs take three to four days to run, Mr. Erickson
says.

Recently,
the shop replaced about half of these machines with newer Citizen
models. Such widespread replacement is a common practice at Highland,
which phases out machines every five or six years to stay abreast of
the latest technology. Mr. Erickson says the enhancements to his newest
machines—particularly design and control improvements—have improved
cycle times by 40 percent.

Replacing machines so often
may seem like a huge investment, but Highland comes out ahead. The
primary reason the shop upgrades machines is not because they are worn
out, but to take advantage of the latest technology. Thus, the old
machines are still valuable, and the shop can get back as much as 70
percent of its investment, Mr. Erickson says. The shop treats the
machines well as a part of a philosophy of treating the workpieces
well.

Value Is The Bottom Line

“We don’t make parts; we make jewels,” he says. That simple statement,
which Mr. Erickson attempts to emphasize to all employees, epitomizes a
key component of Highland’s approach to unattended machining.
Lights-out production is a side effect of a process designed to provide
customers with the highest-quality parts possible.

Many shops put too much emphasis on achieving short cycle times, a
benchmark that misses the point, Mr. Nolan says. At Highland, the goal
is to create a stable overall process that consistently delivers
high-quality parts. If achieving better throughput and higher-quality
parts takes longer cycle times, so be it.

In fact, only
Mr. Erickson and Mr. Nolan know the cycle time on which a given quote
is based. This encourages employees to focus on the big picture rather
than worry about whether they are hitting cycle time expectations.

The
shop’s emphasis on quality extends beyond just finished parts—it
settles for nothing less than top-quality raw materials and other basic
items. As Mr. Erickson puts it, “You can’t put inconsistent things in
and expect consistent things to come out.”

To that end,
the shop pays top dollar for coolant. While $10 to $12 per gallon seems
expensive to some other shops, the coolant lasts long enough to make
this investment more than worth it, Mr. Erickson says. Thanks to a
quality filtration system, the coolant typically stays in the machines
until they are sold. “The bottom line is value, not price,” he says.

All Jobs Are Created Equal

Highland employees don’t think of jobs in terms of “manned” or
“unmanned” because every job is assumed to be unmanned. The shop
designs the process the same way regardless of whether anyone is there
to oversee it.

In
Highland’s view, using different feed rates, speeds and other
parameters based on whether a job is attended doesn’t make sense at
all. Inconsistencies in the way parts are processed lead to
inconsistent parts. “The idea is to develop a good process that you can
use all the time,” Mr. Nolan says.

After creating a
process, Highland views lights-out operation as an added benefit rather
than as something it has to achieve to make money on the job. After the
company proves out the job during the day while operators are present,
it takes a conservative approach to running unattended. For example, if
a cutting tool can handle 500 parts before wear sets in, the machine
might be set up to produce only 250 parts after everyone leaves for the
day. Running this far short of expected tool life ensures that only
quality parts are produced. In the shop’s view, it has produced 250
more parts almost for free—that is, with no attention and very little
extra expense.

“Unattended does not mean 24/7,” Mr.
Erickson says. “We run unattended to get what extra parts we can.
Unattended is used as ‘gravy’—a benefit rather than something we have
to bank on.”

A Holistic Approach To PM

One of
the most striking aspects of the shop’s thinking is that it doesn’t
treat preventive maintenance as a separate discipline with a separate
schedule. Rather, the shop integrates it into production. For example,
operators strip out all tooling and maintenance items and thoroughly
clean each machine after every job. Built-up gunk can impede the gears
of milling sleeves over time, Mr. Erickson says. He’s seen the problem
in other shops. However, it’s a non-issue at Highland, where operators
take out the sleeves and check the bearings after every job.

This
approach to PM is a big part of the reason why the machines keep their
value longer, Mr. Nolan says. In addition, by making each machine “like
new” after every job, employees learn the ins and outs of the equipment
they operate. Troubleshooting problems becomes much easier.

“We
don’t avoid setup, we get good at setup,” Mr. Nolan says. “All these
time-consuming steps we do daily ultimately give us higher throughput.”

Improving The Process

Highland’s approach to unattended machining didn’t materialize out of
thin air—it is the result of following a doctrine of continuous
improvement that underlies practically every operation. To encourage
active participation in this improvement, employees are awarded gift
certificates for good ideas.

The
company’s commitment to continuous improvement is perhaps best
exemplified by a small container of molten plastic in the shop’s
presetter area. After a job is finished, the tools are dipped in the
hot plastic and placed into a drawer with a tag identifying the job and
the name of the customer. When that job comes up again, operators can
reuse the tools. If the tools are worn, the operator can examine the
pattern of wear for clues about how to improve that particular process
and produce even finer-quality “jewels” the next time around.

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